In "Power Rangers Megaforce," the Robots Knight characters, specifically known as the Robo Knight, return to assist the Megaforce Rangers in their battles against the Armada after initially saving Orion for several reasons that revolve around themes of friendship, loyalty, and the ongoing fight against evil.
When Orion is rescued, it reinforces the idea of teamwork and unity among the Rangers. Robo Knight, being a robot with a strong sense of justice and duty, understands the need to fight against the greater evil posed by the Armada, which threatens not only the Earth but all of their home dimensions.
Additionally, Robo Knight's involvement highlights the importance of camaraderie within the team. Despite any initial differences or uncertainties, the characters come together for a common cause, emphasizing the show's recurring theme of unity in the face of adversity.
Robo Knight's return also showcases his evolution as a character, demonstrating that he has become an integral part of the Megaforce team, willing to put himself at risk to protect his friends and the world from the Armada's threat.